The dissertation is divided into four chapters and an experimental section. The introduction describes the biological significance of the reaction of hydroxylamine with nucleic acid components. The following three chapters discuss the results of the author's work, and are virtually independent of each other. In chapter two, previous knowledge on the reaction of hydroxylamine with cytosine is extended to polymers containing cytosine, in an attempt to clarify the mechanism of hydroxylamine mutagenesis. Chapter three describes the lesser-known reactions with adenine and isoguanine. It is followed by a short chapter containing some initial observations on the reactions of other bases with hydroxylamine. This work omits the effects of hydroxylamine on uracil and thymine which have already been adequately described (see, for instance, reference 14). The system for numbering the rings of the natural bases is given below for reference, as it is highly confusing. It should be noted that representation of compounds in particular tautomeric forms does not imply knowledge of the true tautomeric forms.